Abstract

Performance of a laboratory-scale Anaerobic Baffled Reactor (ABR) system
treating chemically adjusted domestic (sewage) wastewater with variable strength of
100-500 mg/L was investigated at anaerobic condition (25-30 °C) for 81 days after
reaching steady-state at different retention time of 1 d, 2 d and 3 d. The evaluation was
made by assuming a series of plug flow growth reactor, so that the results did not give a
realistic interpretation of the data since diffusional limitations were not considered. The
experimental section shows that for all wastewater strength, maximum COD removal of
69% were obtained at loading rates of 0.102-0.306 kg. COD/m3.day have been reported
in the literature review. Removal efficiencies showed very little sensitivity to daily
fluctuations in influent wastewater quality. HRT, pH and wastewater strength have a
significant impact on sulfate removal, and longer retention time, lower pH and
wastewater strength resulted in higher sulfate removal, contrary with nitrite where at
longer retention time and lower pH and wastewater strength there would be an addition
in nitrite. Overall, the ABR like other anaerobic reactors was not an efficient reactor for
anions removal. The main objectives of this study was to study the ability of Anaerobic
Baffled Reactor (ABR) to remove organics from domestic wastewater, as well as to
investigate the possibility of ABR as an efficient, economic and lowly operation and
maintenance, which do not need expertise to handle, compared to other systems. In
order to enhance the commercial potential of ABR, more work still remains to be done
in the following area: COD removal, solids, treatment of toxic wastewater and an
improved understanding of the factors controlling bacterial ecology.